Metastatic Pancreatic Adenocarcinoma to Umbilical Skin.

Sister Mary Joseph nodule (SMJN) is a rare metastasis to umbilical skin originating from internal tumors including the stomach, ovary and large intestine and less commonly from pancreatic cancers. We report an uncommon case of metastatic pancreatic adenocarcinoma to umbilical skin. An 85-year-old female presented with a 1.8 cm protrusion of the right lateral umbilicus. The CT scan showed a 3.5 cm pancreatic lesion, peritoneal carcinomatosis and abdominal lymphadenopathy. Histology examination revealed atypical infiltrative glandular structures. Immunohistochemistry showed positive CK7, negative CDX2 and P53 with mutated patterns. These were consistent with metastatic adenocarcinoma most consistent with pancreatobiliary or upper GI origin. CK7 expresses in the ductal cells in pancreatic ductal adenocarcinoma. While CDX2 is positive in intestinal-type adenocarcinoma, it is negative in pancreatic ductal adenocarcinoma. The diagnosis of adenocarcinoma is rendered based on the presence of a pancreatic lesion in CT scan, positive CK7 and negative CDX2 in umbilical nodule tumor cells in the current patient.